Industry's first SiC power MOSFET with internal SiC SBD reduces power loss in inverters

July 26, 2012 //
By Paul Buckley

ROHM Semiconductor has developed a 2nd generation high-voltage (1200 V) Silicon Carbide power MOSFET designed for inverters and converters in power conditioners for industrial devices and photovoltaic power generation.

Features include low power loss and high reliability, reducing power consumption and enabling support for smaller peripheral components.

The SCH2080KE is the industry’s first SiC power MOSFET to successfully integrate a SiC SBD into a single package. Forward voltage (VF) is reduced by 70% or more for less power loss and fewer components are required.

Current Si IGBTs commonly used in 1200 V-class inverters and converters cause power switching loss due to tail current or recovery of the external FRD, bringing a need for SiC power MOSFETs capable of operating with low switching loss at high frequencies. However, conventional SiC power MOSFETs were plagued with numerous reliability problems, including characteristic degradation due to body diode conduction (e.g. increased ON resistance, forward voltage, and resistance degradation) and failures of the gate oxide film, making full-scale integration impossible.

ROHM has succeeded in overcoming these problems by improving processes related to crystal defects and device structure and reducing ON resistance per unit area by approximately 30% compared to conventional products, leading to increased miniaturization.

ROHM has also succeeded in integrating an SiC SBD, which previously had to be externally mounted, in the same package using proprietary mounting technology, minimizing forward voltage that was problematic in previous SiC power MOSFET body diodes. As a result, the SCH2080KE reduces operating power loss by 70% or more compared to Si IGBTs used in general inverters. This not only provides lower switching loss, but also enables compatibility with smaller peripheral components by supporting frequencies above 50 kHz.

ROHM also offers the SCT2080KE, a SiC power MOSFET with no internal SiC SBD. Both the SCH20801KE and SCT2080KE can be configured based on customer requirements.